The present disclosure relates generally to a FinFET semiconductor device, and more specifically, locally isolating semiconductor fins of a bulk semiconductor FinFET device.
Various conventional techniques exist for isolating source and drain regions included in FinFET semiconductor devices. One approach employs a silicon-on-insulator (SOI) semiconductor substrate, which includes a buried oxide (BOX) layer disposed between a bulk semiconductor layer and an active silicon layer. One or more semiconductor fins are formed on the active silicon layer such that the BOX isolates the source region from the drain region.
Another approach is to form one or more semiconductor fins on a bulk semiconductor substrate. To isolate the source region from the drain region, a dielectric material is deposited locally over and between the semiconductor fins. However, since the dielectric material is deposited on an outer surface of the fins and the semiconductor substrate, the dielectric material is exposed to the surrounding environment. Accordingly, the local dielectric material is susceptible to erosion during gate formation and spacer etching processes. Excess erosion of the dielectric material may increases the possibility of junction leakage at the gate.